1. Thread concept
1.1 comparison between threads and processes
Threads are similar to processes, both of which have PCB s
The underlying functions of both are the same, and both use clone
Processes can become threads
Under Linux, thread is the smallest unit of execution; process is the smallest uni ...
Added by pcwizzzz on Thu, 18 Jun 2020 08:51:58 +0300
IPC (InterProcess Communication) refers to the communication or exchange of information between different processes.
IPC usually includes pipeline (including nameless pipeline and named pipeline), message queue, semaphore, shared storage, socket, Streams, etc. Soc ...
Added by ValdouaD on Mon, 18 May 2020 09:00:24 +0300
1, Date and time functions
1. Function to get the current dateIt's the same. It's different
CURDATE() : Used to get the current date of the system
CURRENT_DATE() Used by the system to get the current date
mysql> select CURDATE(),CURRENT_DATE();
2. Get function of current time
CURTIME() : Used to get the current time of the system
Added by brighton on Thu, 14 May 2020 12:11:49 +0300
In many applications, creating multiple processes is an effective method for task decomposition. For example, a network server process can create a new subprocess to process each request while listening for client requests. At the same time, the server process will continue to listen for more client connection requests. Decomposin ...
Added by vinny69 on Wed, 13 May 2020 07:56:54 +0300
1, Install dependency package and prepare environment.
yum install -y gcc
Depending on the package, you can install it according to the prompts at compile time. But gcc must be installed.
2, 1. Download the tar package, install and start it.
Added by lnfreish on Wed, 06 May 2020 03:49:40 +0300
1. Simple use
Only one jar package of log4j needs to be imported, and the log4j.properties configuration file under the src directory will be loaded by default
1. Print log to console
log4j.properties configuration file content
#Set the log level to info and output to the console
log4j.appender.console = org ...
Added by jay_bo on Mon, 20 Apr 2020 18:53:38 +0300
1. What is socket
Socket is simply a combination of IP address and port, which can communicate with the application of remote host. A host can be determined by IP address, and an application can be determined by port. IP + port can completely determine an application of a host. Socket originated from UNIX, similar to a special file, can be open ...
Added by munuindra on Wed, 15 Apr 2020 11:46:48 +0300
In order to facilitate the development of network applications, Berkeley University in the United States implements a kind of communication protocol Socket on Unix, which enables programmers to access TCP/IP conveniently;
Use Socket of TCP/IP to communicate:
The server program binds a socket ...
Added by boogybren on Fri, 06 Mar 2020 07:30:09 +0200
1, File system view command df
df [options] [mount point]
Display all file system information, including special file systems, such as / proc,/sysfs
Display capacity in customary units, such as KB,MB or GB
Show file system types
Display capacity in MB
Display capacity in kilobytes. The def ...
Added by seventheyejosh on Fri, 28 Feb 2020 09:52:15 +0200